Player-friendly Clay Helton seeks to impose new discipline

Quarterback Sam Darnold lay on his back, bracing for another sit-up. The strength eluded him. He swung his legs up and out and used the momentum to lever himself upright.

His teammates called out a number, and then they slunk back down again.

Tuesday was punishment day at the eighth practice of USC’s training camp. At the end of one of the longest sessions of the summer, approaching three hours, the team did 20 pushups in full pads, followed immediately by a 60-second plank, 20 sit-ups, 20 squats and about 20 burpees.

“Oh that was wonderful,” offensive lineman Toa Lobendahn said. “I was loving it. If you would’ve gotten a close-in on my face, I would’ve been smiling the whole time.”

Such a scene occupies a hallowed place in the football psyche. Players of a previous generation grew up on it. Football movies practically require it. In real life, such punishment . . . doesn’t really happen anymore, especially at higher levels of football, and especially under coach Clay Helton at USC.

Players do conditioning work with the strength coach, which can indeed be grueling (for some programs, on rare occasions, dangerously so). But coaches reserve actual practice time for actual instruction.

Helton possesses an optimistic temperament, quick to correct but almost never volatile. He usually yells at the end of practice — but almost always because he is happy or excited.

Yet Darnold called Tuesday’s the toughest practice session he’s had at USC.

“It kind of reminds me of Pop Warner, high school days,” Darnold said. “It’s super tough. Something I haven’t done since then.”

So why the shift?

“You’re going to have to ask coach Helton about that,” Darnold said, smiling.

Helton has spoken of beginning the season with more focus and discipline. Penalties and mental errors marred last season’s start. Before training camp began, Helton said he would emphasize proper hand positioning in practice and film study to minimize holding penalties. He would punish offsides penalties with quick calisthenics, like pushups, up-downs or a quick sprint.

And missed assignments or confusion with the playbook would be more forcefully corrected.

Rarely does Helton compel teammates to participate in the punishment: Only once last season at a practice open to the media did the entire team run light sprints after practice. The coaches participated then too.

Helton declined to say whether the session Tuesday stemmed from his effort to enforce more mental discipline. He said it would remain “in-house.”

“Typical of any team,” Helton said. “At some point in time you have some team discipline. That was that time. So I’ll leave it at that.”

Sweat dripping from his head after practice, Darnold explained his trouble with the sit-ups by saying that his “core is super strong.”

“But, he added, “I have a long torso.”

Third time’s a … bore

Darnold has played clean football since USC’s first fully padded practice on Friday. He has made decisions more quickly, completed passes with no hesitation and without an interception in four practices.

It has marked a shift from earlier in camp, when Darnold had three passes intercepted during one session.

Helton offered a reason for the change: Darnold was bored.

“It’s one of those things that I told him coming into camp, ‘You’re going through your third training camp, it’s the same install that you’ve had before, don’t get bored,’” Helton said. “After the first couple of practices, he’s really settled in.”

Quick hit

Receiver Deontay Burnett was limited by a sore ankle.

zach.helfand@latimes.com

Follow Zach Helfand on Twitter @zhelfand